Cameras, Formats & Systems — 60 Terms Defined

Pinhole Camera Cameras, Formats & Systems mm A lensless camera that forms an image through a tiny aperture, giving infinite depth of field and extremely long exposures. d = √(2 × λ × f)

Rangefinder Camera Cameras, Formats & Systems A camera focused by aligning two images in a coupled optical system, viewed through a bright-line finder separate from the lens.

Sensor Format Cameras, Formats & Systems mm The physical dimensions of a camera's sensor, which set its angle of view, depth of field characteristics and light-gathering area. Area ∝ width × height

Shutter Actuation Count Cameras, Formats & Systems count The running total of exposures a camera's mechanical shutter has made, recorded in the file metadata.

Single-lens Reflex (SLR) Cameras, Formats & Systems A camera design in which a hinged mirror reflects the taking lens's image up into the viewfinder, then swings clear when the shutter fires.

Smartphone Camera Cameras, Formats & Systems A camera module in a phone, where computational processing compensates for the physical limits of a very small sensor and lens.

Tripod Cameras, Formats & Systems kg (load rating) A three-legged support that holds the camera rigid for long exposures, precise framing or heavy lenses.

Twin-lens Reflex (TLR) Cameras, Formats & Systems A medium-format camera with two stacked lenses, one for viewing through a waist-level ground glass and one for taking the picture.

View Camera Cameras, Formats & Systems A large-format camera consisting of a lens board and film back joined by a flexible bellows, both adjustable in position and angle.

Viewfinder Coverage Cameras, Formats & Systems % The percentage of the recorded image that is visible through the viewfinder. Coverage = finder area / frame area × 100

Viewfinder Magnification Cameras, Formats & Systems × magnification How large the finder image appears compared with the naked eye, quoted for a 50 mm lens focused at infinity.

Weather Sealing Cameras, Formats & Systems Gaskets and overlapping construction that resist the entry of dust and moisture into a camera or lens.